1. Technical Field
This invention relates generally to cylinder liners and particularly to cylinder liners for heavy duty diesel engine applications wherein a combustion seal is maintained between the liners and a metal gasket plates.
2. Related Art
Cylinder liners, typically fabricated of cast iron, are installed in engine blocks of heavy duty diesel engines and are formed on their upper edge with a circumferentially extending step for receiving a steel plate. A circumferentially continuous sealing ridge projects up from the step surfaces and makes contact with the underside of the steel plate with sufficient force and sealing quality to establish a gas-tight seal between the steel plate and liners. The steel plate engages the cylinder head on its opposite side when the head is bolted to the block. The seal between the liners of the cylinders and the plate serving to seal off the combustion chambers.
For various reasons, including improper liner fit and manufacturing tolerances, such a liner may move relative to the block and steel plate during the combustion cycle. Movement of the liner causes the sealing ridge of the liner to wear impairing the ability of the liner to maintain an adequate combustion seal.
In other situations, it may happen that a liner, through improper installation or manufacturing tolerances is set too low in the block such that the sealing ridge of the liner is not clamped with sufficient force by the steel plate to provide an adequate combustion seal. Such a liner is typically formed with an outer flange that fits into an annular recess machined in the block. When installing the liner, a thin, annular shim is typically installed in the recess of the block and engages the underside of the liner flange to position the sealing ridge at the proper elevation for adequate sealing with the steel plate. In the event the shim turns out to be too thin, such that the liner sits too low for proper sealing, the only known present solution to the problem is to remove the liner and install a thicker shim in the recess of the block, after which the liner is reinstalled. This, of course, can be a costly, inconvenient solution to the problem since the liner needs to be removed and reinstalled, which is particularly troublesome if the problem is discovered after an engine has been built.
It is an object of the present invention to provide a solution for modifying the combustion seal of a heavy duty liner that is worn, improperly installed, or otherwise arranged to make insufficient contact with the metal plate to establish a suitable combustion seal without having to remove and replace or reinstall the liner.